Working oil engine



Sept. 4, 192s.

H. JuNKERs WORKING OIL .ENGINE Filed Nov. 17, 1921 III/lll,

Patented Sept. 4, 1928.

HUGO Wilkens, er DESSAU, enum.

WORKING OIL ENGINE.

Application tiled November 17, 1921, Serial No. 515,983, and in Germany December 6, 1920.

My invention relates to oil engines and more especially to a method of working oil engines in which the fuel is injected without the assistance of atomizing air and is ignited by the heat of compression of the air contained in the engine.

My invention further relates to the means for carryingA out the novel method. In engines ofthe kind 'described a valve like throtm tling member, which may act' automatically or may be positively controlled, is -provided at the fuel nozzle for regulating the quantity of fuel to be injected and to time the injection. This arrangement involves the drawback that an injection valve of this kind requires a separate controlling gear while on the other hand an automatic valve is apt to cause trouble, for instance by sticking.

According to my invention, these diicul- 10 ties are removed by the quantity of fuel to be injected being apportioned, the injection timed and the variation of pressure -in the working cylinder during combustion controlled by merely regulating the fuel pump no regulation whatever being eifected and no movable parts being operated at the nozzle.

Thus the fuel injecting device merely con- 4d sists of a nozzle connected to the fuel delivery pipe and whose open cross-sectional area remains constant during operation, the fuel delivery pipe being in permanent communication with the combustion chamber. The size and form of the injector opening are so chosen that the high 'presure required for effective atomization and which amounts to several hundred atmospheres, is generated in the liquid fuel as it is being injected. Heretofore a throttling means at the end of the fuel delivery pipe was considered indispensable in engines of the kind referred to, inasmuch as the fuel supply at the point of .injection must be controlled exactly. Now, the surprising fact has been found that, a1- though many liquid fuels can be compressed to a considerable extent, yet it is possible to effectd a perfectly regular transmission of the controlling operations from the point where these operations start, that is, the pump, up to the injection nozzles, which are as a rule disposed at a considerable distance from the pump. This can be explained by the further fact that with a carefully designed pump and by scrupulously avoiding all air pockets in the fuel supply pipes, no irregularities can arise in the injection between the strokes vso that, after the pump has once been adjusted, injection will go on in an exactly uniform manner, even in a case where the pump is connected with the open injection nozzle by a comparatively long pipe, the content of which may be a. multiple of t-he pump cylinder swept by the piston. In consequence thereof the pump may be arranged at any point of the engine, where it can best be actuated.

The'pump according to my invention may be designed in various ways, but in all cases it is important that the pump shall not only produce pressure, but also apportion the quantity of fuel, this being effected by varying its stroke or the opening of its valves, the time and conditions of the injection being predetermined by the same means.

Preferably, the pump drive is made adjustable, while its valves are automatic.

In the drawings aiixed to this specification and forming part thereof7 a' two stroke cycle engine embodying my invention is illustrated iagrammatically by way of example,

Fig. 1 being a partial axial section, and,

Fig. 2 a plan.

Referring to the drawings 1 is the cylinder and 2 and 3 are two pistons reciprocating therein in opposite directions and actuating the coupled shafts 4 and 5. Fuel is supplied through a nozzle 6 arranged in the wall of the combustion chamber. The narrow opening 7 required for atomization is open towards l the cylinder as well as towards the fuel supply pipe 8, so that this latter pipe is in permanent communication with the combustion chamber.` The supplying, apportioning and compressing of the fuel and the timing of the injection are effected by the fuel pump 9, whose piston 1() is directly propelled by a cam 11 on shaft 4 and pulled back by a spring 12.

The pump is further provided with the usual suction and delivery valves 13 and 14, respectively. The regulation of the quantity lof fuel injected and the timing-of the injection can be effected by varying the lift. and pei-. riods of stroke of the pump piston for example by means of a conical cam adapted tobe displaced axially on its shaft. By employing' y 69v vtion temperature of the fuel, pumping liquid a cam of suitable configuration beginning and end of the piston stroke and in consequence thereof `the periods of injection, the variations 2 which shows the shaft 4 with the cam body fixed to its free end and secured against rotation by means of the key 20, said cam body being however adapted to be readily displaced and carrying a tapering cam 11 which serves to actuate the pump piston 10.- At the end of shaft 4 there is arranged a centrifugal governor 21 which, on the number of revolutions changing, axially displaces the cam body 15 by aid of rods 22, v whereby a higher or low'er point of the cam, according to the number of revolutions and the load on the engine, respectively, is carried in front of the pump piston, thus causing .more or less fuel to be ed into 'theenginecylinden p j 4 In designing and arranging the pump and the fuel supply ipe, care should be taken'to avoid all air poc ets inasmuch as they would disturb the positiveI connection between the operation of the pump and the injection offuel in the cylinder As appears from the drawing, an engine designed in accordance with the present invention is particularly simple, nol movable parts whatever being connected with the cylinder 'and the only control member requiring to be o erated in synchronism with the engine, viz, t e ump bein vactuated directly from the cran shaftoft e engine.

I This simplification offers articular advantages in multi-cylinder engines, where the fuel pumps can be combined 1n a single casting and can be regulated in common. Although such an arrangement requires fuel deliver pipes, yet regular operation is rendere possible bythe invention.

V'IclaimL 1; The method of operating oil engines of the solid injection type which consists in compressing air in the working cylinder to ignition temperature of the fuel, pumping liquid fuel in attenuated condition directly into the compressed air in substantially constant timed relation to the commencement ofthe working stroke of the piston so as to ignite said fuel, and re ulating the period of combustion exclusive y by means of the fuel delivery Tplump.

i 'the solid injection type which consists in conipressing air in the working cylinder to ignifuel directly into the com ressed air during the workingyst-roke of 't e pistonz in suc 'b manner ias'tol 'cause ignition of said fuel sub-` stantially coincident with the commencement 'of the working stroke for all load conditions,

e method of operating 'oil engines of and maintaining the period of combustion throughout the period of injection through the pumping means, according to variable load conditions.

3. The method of operating oil engines 4of the solid, injection type which consists in compressing air in the working cylinder to ignition tem erature of the fuel, thereafter pumpin iquid fuel under high compression directly into the compressed air so as to atomize and i ite said fuel immediately upon its .entranceinto the cylinder,l and regulating the pumping means to apportion the fuel and control the period of injection of the fuel in proportion to varying load conditions.

4. The method of operating oil engines of the solid injectiontype which consists in compressing air in the working cylinder to ignition temperature of the fuel, pumping liquid fuel directl into the compressed air so as to ignite said uel upon its entrance into the cylinder, and regulating the pumping means to apportion the fuel and simultaneously control the period of injection and combustion of the fuel.'

5. An oil engine of the solid injection t pe comprising in combination a working 'cy inder and piston arranged to reciprocate therein in such manner as to compress the airin said cylinder up to ignition temperature `of the fuel, a fuel pump, a normally open fuel passage leading to the cylinder therefrom, and' means for actuating said pump'during working stroke of the piston to introduce the fuel directly into the cylinder, said means alone ap ortioning the quantity of fuel injected and controllin the period of combustion and being arranged to initiate the injection substanti ally coincident with the commencement of the working stroke of the piston aforesaid.

6. An oil engine of the solid injection t pe comprising in combination a working c nder and piston arranged to reciprocate t erein in such manner as to compress the air in said cylinder up to ignition temperature of the fuel, a high pressure fuel pump, and engine operated means for actuating said pump during workin stroke of the piston to introduce the fuel ire'ctly into the cylinder, said means bein operable to initiate the injection substantial y at the same point of the crank circle under all loads and to vvary the effective stroke of the pump1 according to changing load conditions to t ereby regulate the quantity of fuel injected and the period of combustion to accord with the period of injection.

7. An oil engine comprising in combination a working cylinder, a piston arranged to revOli iis

ciprocatetherein in such manneizas to compress thevair in said cylinder up to ignition temperatureY of the fuel, a'high pressure fuel pump, afuel conduit leadin from said pump cam slidably mounted 0n the engine crank Without varying the point of initiation of its shaft having its operative surface arranged operation, said pumping means being thereto initiate operation of the fuel pump subby arranged to place said fuel under pressure, 10 stantially coincident with the commenceapportion the fuel injected,`and control the 5 ment of the working stroke of the engine pisperiod of injection and combustion.

ton and shiftable during operation ofthe en- In testimony whereof I affix my signature. gine to vary the eective stroke of said pump HUGO J UN KERS.` 

